時下逆變器的目標是將直流電源的電力轉換並輸送到交流負載或交流電網。由於大多數的再生電源都是直流電壓源，因而轉換與整合直流電源至電網已成為重要課題。為此而組成的轉換系統須具有一定水準如高可靠度、小型化以及低成本。而要達到這些水準，應該採取兩個手法，即為使用合適的逆變器型態以及高效能控制方法。在很多研究文獻上已提出了有關單級直流/交流電力轉換的逆變器型態，差動升壓逆變器是一種可以將低電壓直流電源升為高電壓交流電的型態。此種型態在所有逆變器中是很突出的，因為它是由兩個雙向升壓轉換器所構成。由於該兩個轉換器的每一個都會產生具有直流偏壓的交流電壓，因而逆變器交流電壓輸出是差動的，來自於該兩個轉換器的電壓差額。
在本研究中設計並實施了單週期控制法應用於一個差動升壓逆變器，此種控制方法乃因其高速動態與良好抗擾動能力而被優先採用。單週期控制法可基於即時積分器的三角形法則，而循跡於電源轉換器的可變參考電壓。依此，該控制方法有能力去追隨含直流偏壓的交流電壓參考值，並抵抗輸入電壓上的擾動。為了將該差動升壓逆變器連接到電網，本研究實施了相移功率控制方法。在此方法中，所注入於電網的功率是由該逆變器的輸出電壓相位移所控制。該功率控制法被設計成，藉由零虛功參考值而達成單一功率因數，進而只有實功率會被注入到交流電網。本研究以模擬與實驗兩方式來驗證所設計的控制器，能達成可接受的總諧波失真率，而接近單一功率因數。

Nowadays, an inverter is purposed to convert and deliver the power from a DC power source to either the AC load or the AC grid. The conversion and integration of DC power source to the grid system become important since most of the renewable power sources are DC voltage source. There are some criteria that should exist in the configured conversion system such as high reliability, compact and low cost. To meet those criteria, two important strategies should be considered i.e. implementing a proper power inverter topology and designing high-performance control method.
There are many inverter topologies proposed in many references for single-stage DC/AC power conversion. Differential boost inverter (DBI) is a kind of topology that can boost a lower voltage of the DC power source to a higher AC voltage. Among all the inverter topologies, this topology is very attractive since it is constructed from two bi-directional boost converters. Since each of the converters generates a DC-biased AC voltage, the inverter generates a differential output AC voltage which is obtained from the output voltage difference of the two-converter.
In this work, one-cycle control (OCC) method is designed and implemented in a DBI. This control method is preferred to be implemented because of its advantages such as fast dynamic response and better perturbation rejection. Based on the triangle rule of the real-time integrator, OCC can track the variable reference voltage of the power converter. Therefore, the control method has an ability to follows a DC-biased AC voltage reference and to handle the input voltage perturbation.
To connect the DBI to the AC grid, a power control shifting phase (PCSP) method is implemented in this work. In this method, the injected grid power is controlled by means of the inverter output voltage shifting phase. The power control is designed to achieve a unity power factor (PF) by implementing a zero reactive power reference so that only active power is injected to the AC grid. Both simulation and experimental have been done to verify that the designed controller can achieve a unity power factor with acceptable THD level.

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